First trimester
Learning Center
Nausea during pregnancy: A good thing?
Morning sickness is common during pregnancy. Understand what nausea and vomiting might mean while you're pregnant.
Implantation bleeding: Common in early pregnancy?
Implantation bleeding is a common early pregnancy symptom. Understand why it happens.
Birth control pills: Harmful in early pregnancy?
If you took birth control pills before you knew you were pregnant, the risks of birth defects are low.
1st trimester pregnancy: What to expect
The first few months of being pregnant can bring physical and emotional changes, such as breast tenderness, nausea, anxiety and excitement.
Keratoconus
When your cornea bulges outward, it can cause blurry vision and make your eyes sensitive to light. Find out about symptoms, causes and treatment for this eye condition.
Trichotillomania (hair-pulling disorder)
In this mental health condition, people can't resist urges to pull out hair from their body. They do this often. Therapy may help reduce or stop urges.
Narcolepsy
Learn more about this sleep disorder that causes periods of involuntary sleep, sleep paralysis and early rapid eye movement (REM) sleep.
Brain AVM (arteriovenous malformation)
Tangled blood vessels in the brain affect typical blood flow in this rare condition. Learn more.
Prenatal care: First trimester visits
Prenatal care can help ensure a healthy pregnancy. Here's an overview of first trimester visits.
Fetal development: The 1st trimester
Fetal development begins before you even know you're pregnant. Here's what happens early on.